The Official (and only) Optical vs. Coaxial Thread

[Taxi]

This is the first thread on this subject. Ah, the good old days.

This thread probably has the most info, but it got ugly and we had to close it. (Edit - After re-reading this monstrosity, I noticed that most of what Justin posted in his long post there on page one had very VERY little to do with discussing digital cable specifics. Instead, it goes off on a tangent of analog wire [which everybody agrees effects audio signals noticably] and CD frequencies and word sizes. -Taxi)
Wash.
Rinse.
Repeat.

There are other threads in the forum about this. (A lot.) But these are the main ones.

[Istagi]

Optical and coax both suck. I use a 20Ghz wireless system and it works great, an no my hair loss has nothing to do with it.

[MrTony]

Thankfully, I have no choice. My player only has coaxial outputs.

[Enzian]

And remember; Don't look at the laser! You could burn your eyes out with that .25w LED!!

How many times have you heard that?!?!

Digital Coax is digital - but Optical is analog!! You see, light is actually a wave...

[Enzian]

I'm sorry - it was DTS that was analog.

[brian]

Good old jspartan...I actually had some civilized conversations with that guy

[AirSickMoth]

Here are some interesting Articles that I found.

http://www.audiovideo101.com/learn/a...nid=101&List=7

and

http://www.taralabs.com/industry_rev...ism_d2_htm.htm

[Mr. Furious]

The problem with many of the sources reporting "the true deal with Optical vs. Coax" is that they all have a vested interest in keeping the cable market alive. As long as there are people willing to pay thousands on cables, there will be a market to supply it. With the increased pressure to scientifically quantify the value of a digital interconnect, we're seeing more cable and HT sites (who often make ad revenue off of cable suppliers) making the case for expensive cables. However none of them are actually showing any real world statistics, scientific studies, or even raw data to support their argument. It's always an article based on theory (or limited / single user experience).

I'm willing to keep an open mind about this. I believe that there is a potential for "bit differences" between the different mediums. I believe that some error may occur due to a poor medium, but I also believe that any well designed digital system will have error correction. I'm not convinced that digital components cannot compensate for problems in the bit stream. I cannot believe that we're the only ones who have thought about buffering Audio/Video and resending the data when there is an error.

Further, evidence in other fields tells us that digital systems operate very consistantly from one application to another. AV is not a completely separate entity. That is not to say that there isn't any unique challenges - simply that some knowledge from one digital system can be applied to another.

Why has no one been willing to run a study on this? Could we come up with the conditions of a challenge / study?

[Wirehed]

I have the two largest audio/video stores in Sac willing to provide the space and products (various cables and speakers etc). I just have to set up the rest of it.

[1138]

Serioulsy Seamonkey, I'd be willing to come up for it. And any other people within a decent range are morethan welcome. Maybe we can set up a meet/test thing.

[Taxi]

I'll drive down, and take anybody who wants to go from the NW area. (Chromy/Thanos/chlngr1970/Morticia/Slade?)

[Mr. Furious]

What are the conditions of the test? How will certain things be insured?

Example: Volume settings, quality of equipment, random use of cables, studio group, double blind test conditions, etc.

What are we attempting to prove in this test - subjective listening tests or bit stream evidence from the decoders? Are you testing cheap coax vs. expensive coax?

I'm sorry I'm so far away - I'd love to be there!

[1138]

Strictly subjective. I'd work on settingup some thorough double blind tests. Not only satisfingly random but do eneough of everything too so that sample size isnt a problem (well, less of one I guess).

[Wirehed]

I'm thinking of using Audio F/X since the owner and a lot of the employees are really cool. Plus they don't care what people think. (as opposed to the other store that has expressed interest in letting me do this, they are an "official" supplier of Monster Cable and act, well, rather pushy).

http://www.audiofx.com/intro4.htm


I'll talk to the owner about how best to set this up. I'm thinking after closeing hours would work the best.

[Miggy]

I'm too far away as well, otherwise I'd be interested. I hpoe to see a detailed report afterwards!

Miggy, the Thief

[Wirehed]

I'm going to hire a writer to cover this "event". It will probably make a great story.

[tomdkat]

Hey 1138, I'm up in Hayward so you could pick me up on the way...

Peace......

[Reznor007]

The best way to do a test like this is to use the same equipment in every test, and only change the interconnect. You will want to use whatever is the best equipment at that particular store also.

Be sure to try everyting from the very cheap coaxial cable included with most components, very basic optical, and all the way up to the $10,000/3 foot coaxial cable in a blind test.

My own view on this is that is there were such huge differences in the digital signal, the decoder wouldn't be able to tell what was DTS/DD and what was PCM or anything else.

[Enzian]

Originally posted by Reznor007
My own view on this is that is there were such huge differences in the digital signal, the decoder wouldn't be able to tell what was DTS/DD and what was PCM or anything else.

Which is the conflicting idea behind this whole debate. If a digital signal is just a string of bits, to be error corrected using ome sort of OSI model; then what difference does it make? If there's a standard (say, DTS) then the player Tx DTS bitstream to the reciever... 1001010011001010010010010
is 1001010011001010010010010 no matter how it gets to the reciever. If, for some reason, the reciever Rx 1001010011101010010010010, it will be error corrected, I assume, on some level.

So, if 1001010011001010010010010 gets to the receiver via digital coax or if 1001010011001010010010010 gets to the reciever via an optical conx - what difference does it make?

And, if you swing by Boston on your way to the demonstration, pick me up!! I'd love to be disproven.

[1138]

I totally agree. It's not like with analog where minor changes affect in minor ways. It's been encoded, and if the information isn't right, it won't be decoded correctly and you get nothing (or something horribly wrong).

As an example (and this is overly simplified), what if I want to send 67. In binary, that's 1000011. Now, if the signal gets delivered wrong, who's to say how bad the outcome will be. If I read 1000001, then I get 65. Not too bad. If I read 11000011, then I get 99. Yowza. If I read 0000011, then I get 3. Oops. With a digital singal, minute changes cause both big and small changes.

[Wirehed]

Like I have siad before, that seems to be rational. However, obviosly (to me) there is something else at play here becuase all the cables sound different to me. And not by just a little either, I'm talking about a difference that should be easily observed.

[Taxi]

Yes, but differences can be "perceived" when there is an "expected" difference.

That is why it would be cool to do some double blind (or at least single blind) tests and see if you really can hear a difference.

The mind can play some amazing tricks on us..

[Tyler Durden]

Oh no! Not this old chestnut - The argument about digital being 1 and 0's is soooo old hat now and I have supplied vast amounts of reasearch previously to back up why. What I am interested in knowing is if 1138 and Taxi thinks that all DVD players and CD players sound exactly the same - the natural conclusion of their argument is that this is so. So my question is this - are you honestly saying that a $75 cd player will sound exactly the same as a $4000 cd player and are we all being conned? And will a $125 DVD player gives as good a performance - aurally - as a $4000 player? Surely if digital data is digital data (as you say) then they must!

[AirSickMoth]

Originally posted by 1138
I totally agree. It's not like with analog where minor changes affect in minor ways. It's been encoded, and if the information isn't right, it won't be decoded correctly and you get nothing (or something horribly wrong).

As an example (and this is overly simplified), what if I want to send 67. In binary, that's 1000011. Now, if the signal gets delivered wrong, who's to say how bad the outcome will be. If I read 1000001, then I get 65. Not too bad. If I read 11000011, then I get 99. Yowza. If I read 0000011, then I get 3. Oops. With a digital singal, minute changes cause both big and small changes.

Well, I'm not sure what kind of error checking a DD/DTS decoder has, but I assume it has it. The simple error checking on a computer does quite a bit (hehehe, "bit", is that a pun?). Any thing that is transmited in a computer is error checked on some level. If it didn't your computer would crash all the time (more than it does now for some of you).

When you send a string of bits, it comes with an error checking table. When you compare the bits in the table to the bits in the string, you can figure out if there was an error in the string. Using the error bits and redundancy bits, you can reconstruct the bit string like it was supposed to be. It is fairly simple and often done in hardware.

So, if some bits arrive before or after they should, the error checking should take care of it. Unless the error is very big.

Here is a small article dealing with Error checking on CDs

I'll try to look for better Error checkng stuff tomorow.

[Wirehed]

Originally posted by Taxi
Yes, but differences can be "perceived" when there is an "expected" difference.

That is why it would be cool to do some double blind (or at least single blind) tests and see if you really can hear a difference.

The mind can play some amazing tricks on us..

Yes, I agree with you here. BUT... one of the big differences with the different cables is the amount of base. The better the cable, the more bass I get.

One of the things I noticed with all the different cables I used was that the better cables would make the windows vibrate, and some cables would make the framed artwork in my house vibrate.

This isn't something I was just perceiving, it was actually happening. If I had been using a sound meter at the time, I'm sure there would have been a notable difference.

[Morticia]

Originally posted by Taxi
I'll drive down, and take anybody who wants to go from the NW area. (Chromy/Thanos/chlngr1970/Morticia/Slade?)

ROAD TRIP!!

twist my arm.....am I too late?

[1138]

Originally posted by Tyler Durden
The argument about digital being 1 and 0's is soooo old hat now and I have supplied vast amounts of reasearch previously to back up why.

Where? I'd like to see it. Really.

So my question is this - are you honestly saying that a $75 cd player will sound exactly the same as a $4000 cd player and are we all being conned? And will a $125 DVD player gives as good a performance - aurally - as a $4000 player? Surely if digital data is digital data (as you say) then they must!

If you're using a digital connection, and they both have the same bit bandwidth, then yes. Why not? Why use digital in the first place if it's no better than analog? Are we all being conned?!?!?!

So are you saying that a $25 CD-ROM drive will do a worse job of copying game files over to my computer than a $250 DVD-ROM/CD-R drive? Will I not have the game copied correctly?

I'd like somebody to explain to me just how these digital signals come out sounding different. Technical details with no limits. I can't honestly see how they could unless both Dolby and DTS have designed some of the worst digital compression schemes known to man. The fact that I either do or don't get my satelite signal from miles up in space to my house (with a working capability at about 60% correct bits) demonstrates the capability of digital encoding.

[Wirehed]

Nope, you aren't too late. Sign up now, only $19.98...


I don't know how we can set up a double blind test is the only problem. The best we can probably do is have someone swap cables out while we are in a different room. Not scientific by any means, but at least good for argument sake.

If anyone has some ideas for how to set this up, please let me know.

I'll start setting up a time/date with Audio/FX.


An interesting side note; Audio/FX is in the front parking lot of a hotel. I could find out rates if those of you driving if from Oregon are interested. Let me know.

Audio/FX is open 7days a week and they are usually packed. Probably the best thing to do is set up an evening time so we can do this when they are closed.

[1138]

I'll work on testing procedures. Put some of that probability and statistics course to use.

[Mr. Furious]

My impression that most of the differences in DVD players were due to image quality (plus other features). When players are reviewed, I don't often read much on the audio qualities - mostly just the video image. Plus we can't discount that some differences in cost might be in quality of construction, markup for brand name, reliability and warranty, etc.

My $0.02

[Wirehed]

Originally posted by 1138
I'll work on testing procedures. Put some of that probability and statistics course to use.

Cool.

When do people want to do this?

[Taxi]

Originally posted by Seamonkey


Cool.

When do people want to do this?

Let's move that discussion here. Thanks.

[Tyler Durden]

I have posted loads of reasosn as to the validity of my argument but please let's not go over all that again.

But 1138 you really are beginning to talk utter nonsense now. All CD players do not sound the same - just as all DSP's do not sound the same, just as all AD/DA convertors do not sound the same, just as jitter is known (absolutely known - quantified, studied, known) to 'colour' the sound that one hears. To say otherwise makes a mockery of all the work that 1,000's of engineers have put in to this kind of research and is the height of arrogance. Digitla is not a perfect medium by any stretch of the imagination - error correction, jitter, DSP's etc etc etc all play a part. The compression system used by both Dolby and Dts IS rather crass and far from perfect.

Are you seriously telling me that my Lexicon MC-12 sounds the same as a Sherwood??? Come over to my home, sir and I will prove to you that a Lexicon product does not sound the same as those made by Sherwood - even when partnered with the same equipment.

And yes I am telling you that the copies you make of your game will be corrupted and contain errors. There is no such thing as a clone when it comes to mastering. Ask those who master CDs, DVDs etc for a living. Why else we do we have a 'Glitch Exhaust' part on this forum where not everyone suffers the same glitch even when playing the same movie on the same player??? It's normally called a mastering error and these can happen even in a single disc from a batch made at the same time.

Also, if you are going to hold a 'test' can I ask exactly how it will be conducted?? Blind tests are notoriously difficult to pull off even for those who have been doing them for many years!

[1138]

While I don't want to get into insinuations of "arrogance", I don't think I'm talking nonsense.

DSP, AD/DA, etc. Those all have something in common. They have an analog part to them. They convert analog to digital and vice versa. So of course those won't all sound the same. But then, since they're all analog in part, why are we even discussing them in a thread about digital cable?

And digital is most often a perfect medium. That's why we use it. It's not some sort of super analog system. The whole point of digital is to have a system that is pretty much independent of medium. You can send at one point and reconstruct on the other.

And yes I am telling you that the copies you make of your game will be corrupted and contain errors. There is no such thing as a clone when it comes to mastering.

Yes, there is. If my game doesn't copy over correctly, it won't work. As I've stated before, you can't just make minor changes in digital information and expect only minor results. That's not how it works.

If digital transmissions were so prone to error, things like the internet wouldn't work. How is it we all read the same text on every document we read on the internet? Or I guess we don't because the "digital" connection is so prone to errors. Hey guys, I'm not a bad typer, it's just your crappy $80 cable modem. If you invested in a $500 cable modem, I'd never have any typing errors and my grammar would improve too.

Are to honestly believe that when I copy a .jpg from a CD-ROM drive to my HD, the reds become less vibrant?

You mention error correction as proof that digital connections can't trannsmit the correct info? It's called error correction for a reason. It corrects info that iw wrong. As I mentioned, my DTV satelite system can manage to maintain the signal with only a 60% bit integrity. Now naturally, they have a more heavy duty error correction stream than most. But they probabaly need it more than most seeing as how they send their signal over the air through the entire atmosphere of the earth over the entire US. And the thing is, if you're getting the sat picture, you're getting it full on. There is no in between. You'll know when it's gone bad because it all gets hosed or cuts off.

As to the Glitch Exhaust, most of those problems have nothing to do with bit error. Most are due to software incompatibilities. They're essentially programming bugs in how the DVD was created, not mastered. And it seems that most of the other problems are mastering errors, but not of bit error but more of physical media. A bad batch is bad because the media has some problem. Certainly that's what the infamous "DVD rot" is supposed to be.

As for the tests, if you've read this thread, you'll see that I'm going to work on the testing process. It hasn't been finalized yet. And I'm very open to suggestions from anybody who wants to make them as to procedures. Granted, these tests won't prove bit integrity, but are more designed to examine the ability to tell the difference in digital cables.

So anyway, so far most of the stuff you've mentioned Tyler have nothing to do with the discussion of digital cables and their quality and/or bit integrity in digital transmissions. You're either off in the analog world or talking about something else entirely. But like I said, I'm very open to examining and discussing any actual examples and or proof of what you're saying, no matter the technical details.

[Miggy]

If you invested in a $500 cable modem, I'd never have any typing errors and my grammar would improve too.

Let's examine this logically. The DVD or CD player sends out the audio information in digital format (0 and 1). With optical connection, this information gets sent in the form of light waves, which then arrives at the receiver, is processed, corrected (if necessary), then converted to analog. With coaxial, the digital information is sent along as pulses of electricity, which then arrives at the receiver, is processed, corrected (if necessary), then converted to analog. Now, assuming the reciever only has one DAC, the only possible difference would be in the circuitry going from the optical input to the DAC and the coaxial input to the DAC. But, I can't see even that and especially not enough difference to have it add more bass one way or the other.

Miggy, the Thief

[Taxi]

Tyler, your attitude on this subject is neither appreciated nor acceptable.

If you can't find a civil way to discuss this topic, then please do not discuss it. Terms like "talk utter nonsense" and "height of arrogance" are not acceptable on this forum. If you think you can refute what 1138 asserts, then do so with facts, or at least be a bit informational. Emotional outbursts like "Are you seriously telling me that my Lexicon MC-12 sounds the same as a Sherwood???" come off sounding like you're trying to rationalize for yourself spending $8000+ (US) on a piece of HT equipment. At the same time, you show that you're not even paying attention to what 1138 has written. Of course High-End Digital converters are worth the money, because they produce a better analog signal for your Parasound amplifier to send through your Nordost cables to your B&W speakers.

All that 1138 has ever proposed is that the signal coming from your high-end DVD transport looks EXACTLY the same when it leaves your high-end transport (or lowly Oritron DVD player) as it does when it enters your Lexicon Digital processor (or cheap Sherwood receiver) whether you're using digital coaxial cable or optical cable with toslink connectors (gold plating optional). That's it.

And I can accept that because I know that with all the data that gets sent back and forth between the RAM and HD on my computer, which uses the SAME DIGITAL DATA as digital home theaters (1's and 0's), if there were variations (even slight) in that data, that my HD would become corrupted, and at an alarmingly fast rate.

However, he never said nor even implied that a system built on high-end components (save for digital interconnects) will sound the same as a low-end system. So get over it already, will you?

[1138]

Well, actually, I would say that, if you're using a digital connection, any device (disc reader) should sound the same. IMO. Every player uses a laser to read the digital information off of the disc and then send it to the receiver. At no point is it converted to analog until it gets to the receiver. So, as long as we remain all digital until you reach the receiver, I don't see how it could sound different.

Now, if you were using the analog outs on the disc reader, I could definitely see how there could be sound differences. Because then we're getting back into the D/A domain.

But with digital connections, I don't see how any player could sound better than another (unless one had a lower bit bandwidth on it's digital connection).

[Wirehed]

See that's the crux of it. I totally understand what 1138 and Taxi are saying, it seems to make perfect sence. However, I sure as hell can tell a HUGE difference between CD players. Even when they are using the same coax (digital) cable.

[Taxi]

We'll see about that.

[Tyler Durden]

Oh for goodness sake, Taxi. What's happened to this forum recently??? I am not being offensive in any way to anyone. Is a little passion not allowed on here any more - must we tip-toe around each and every forum member as though on eggshells? I will not apologise as I have nothing to apologise for but IMO 1138 is talking nonsense - as I'm certain he thinks I am too! As for being 'informational' - can I refer you to your own links at the top of this thread? I think you'll find more relevant information there to the topic at hand than anywhere else. Must say that I'm glad you read my posts thoroughly though as you have clearly made a note of my equipment list! Using Chord cables at the mo though - which while clealry of no value to HT users such as yourself who see no benefit in cables - have made a vast improvement to my listening pleasure!! :p

Also, I love the way you've edited the header to this topic - ha ha ha ha - nice one! Like it a lot! But clearly you didn't read the previous monstrosity very well. Could you point out precisely which part of the thread was not about digital?? I have just re-read it and found only a very small amount of information that related to analogue interconnects. A VAST chunk of it deals quite obviously and specifically with the digital medium. Can't be bothered to cut and paste which bits as there's far too much info and it will clutter up this thread still further...

I think the the reams and reams of info that I posted at the links already given do prove a point - as, indeed, do some of 1138's posts. There is a validity of kinds to both arguments. It is irritating for me (and this you must understand) that working within the industry and knowing people who have expended great time and effort on some of the subject matters touched here that people on the net on forums such as this can simply rubbish much of their work with impunity and some of 1138's inferences are arrogant - as are mine! It should also be pointed out that I am in the lucky position of being able to use HT equipment as part of my job so I think it unlikely that I would be having an "emotional outburst" and trying to "rationalise spending $8,000+" when I have in fact spent $0. But I find it galling that 1138 attempts to assert that there is no difference between components (many of which have had 1,000's of man hours poured into their development and manufacture) because of, what I firmly believe, to be a misguided notion.

Show me the technical information 1138 that goes some way to proving your own point and we can talk further!

What I have posted above is relevant to a greater understanding of the digital medium and are important points to take into account when looking at the subject as a whole.

I am happy to offer 1138 and a small group of forum members access to the facilities that I have available to me to conduct the test. This will ensure that the test takes place in a controlled and un-biased environment and conducted by those who have a long experience with this kind of investigation. Any mods are welcome to mail me privately and we will see what can be arranged.